RMA'd P5N72T Premium - sell, swap or keep?

Well, it seems my first thread has degenerated into a discussion about the best way to remove thermal pads. Apparently it's Akasa TIM-Clean with an IPA (isopropyl alcohol) chaser. Um, yay?

But there was one question I did want answering, which didn't get answered. It's more of an opinion thing, a "What Would You Do?", if you will...

A few of you might have heard about the 15-month-old ASUS P5N72T-Premium I RMA'd back in January. Well it's finally returned from the netherlands of the ASUS RMA department, and... they've opted to replace it with someone else's return: what they've sent me is a board that has two "RMA RETURN" stickers, one "RMA QC TEST" sticker, and no less than four different serial numbers...

I intend to test this board, despite my better judgement suggesting that it's probably in similar working order as the one I sent back... i.e. it's destined for retirement as dustbin filler. But anyway, that's not the point.

I've already replaced the P5N72T with a Rampage Formula, which is doing sterling service in my desktop system. Aside from the fact the RF won't run the memory at full rated speed (I get memtest86 errors and BSODs if I run it any faster than 800MHz, even with only one stick; the P5N worked nicely up to the 1066MHz rating of the RAM). Other than that, the P5N72T is based on an nForce 780i SLi, while the Rampage Formula is Intel X48-based and runs Crossfire instead of SLi (which doesn't seem to affect my GTX260, but that's only a single card).

So assume for a minute that you're in my boots and that the RMA-replacement P5N works fine. Do you:
A) Ebay the P5N and be done with it. Bear in mind this thing cost me £120-odd, plus about £20 in P&P to send it back.
B) Keep the P5N as a spare and continue using the Rampage
C) Swap the Rampage for the P5N and keep the Rampage as a spare
D) Swap the Rampage for the P5N and ebay the (~3 month old) Rampage.

I'm tempted to keep using the Rampage because for all its faults (the RAM speed issue and if you plug the "LCD POSTer" status display in it fails to POST, lol) it seems to be holding up quite well. Oh, and the headphone output doesn't have the I/O/CPU-synched squeal that the P5N did.... so it's much nicer to use with headphones

I also noticed that there were some "interesting" comments on Newegg's product page for the P5N72T. "Dead on arrival", "RMA'd, but replacement was dead!", "A positively excellent paperweight!" and so on. Roughly half the reviews seemed to be negative, with only a couple of 4- and 5-star tags. The Rampage Formula doesn't seem to have received anywhere near as much scrutiny...